As the EPA requirements are being applied to off highway vehicles of the work machine type, there is an ever increasing demand placed on the propulsion system to produce sufficient power for vehicle movement and accessory loads as well as doing so with a high degree of fuel economy and newly required emission limit standards. These standards require many additional devices to provide an engine and aftertreatment system that meets the required levels of particulate and nitrous oxide emissions. One approach to help achieve these ends is to provide a generator driven by the diesel engine and coupled to an electric motor which, in turn, drives a standard propulsion system for the vehicle.
One of the problems in adopting this approach is that the existing transmission system for the vehicle, very often, needs to be retained in the power train so that the mounting and installation of the motor and generator, by their nature having significant volume, must present a difficult problem incorporating them and integrating them into the overall propulsion system.
Accordingly what is needed in the art is a system in which the motor and generator are compactly mounted within the propulsion system for a work vehicle.